Hood for oxygen therapy



April 1947- c. J. LAMBERTSEN EI'AL 2,418,473

HOOD FOR OXYGEN THERAPY Filed April 20, 1945 2 Sheets-Sheet l J4- P 20 z avwcvlfo'co Ghri -fian JLalmberfsen L/nco/n Godfrey 4 b; q flfwk w afloznur April 8, 1947.

C. J. LAMBERTSEN EI'AL HOOD FOR OXYGEN THERAPY Filed April 20, 1945 2 Sheets-Sheet 2 atfozmmga Patented Apr. 8, 1947 HOOD FUR ()XZGEN THERAPY Christian J. Lambertscn and Lincoln Godfrey, United States Army Application April 20, 1945, Serial No. 589,449

(Granted under the act of March 3, 1883, as

amended April 30, 1928; 3'70 0. G. 757) 6 Claims.

The invention described herein may be manufactured and used by or for the Government for governmental purposes, without payment to us of any royalty thereon.

This invention relates generally to oxygen therapy apparatus but more particularly to a transparent hood adapted for the administration of oxygen.

One object of the invention 'is to provide a small, light-weight oxygen hood which may be easily applied and taken care of by the nursin stair, and which makes nursing of acutely in patients who need, oxygen a great deal easier.

Another object of the invention is to provide an oxygen hood which permits such procedures as intravenous injections of fluids and medications, enemas, bed baths, X-ray photography and electrocardiography without removing the patient from the hood.

Another object of the invention is to provide an oxygen hood in which the patients chest and abdomen are accessible for examination, and one in which his head and face may be easily inspected.

Another object of the invention is to provide a transparent oxygen hood which provides for the patients visibility without any distortion and by which patients who ar not acutely ill are able to read or write without eyestrain or inconvenience.

Further objects and advantages of the present invention will be apparent from the following description reference being had to the accompanying drawings.

Referring to the drawings in which like parts are indicated by similar reference characters:

Figure 1 is a perspective view showing the assembled hood placed in operative position;

Figure 2 is a sectionized View taken on a longitudinal plane through the center of the hood;

Figure 3 is a plan view showing the hood in operative position;

Figure 4 is a perspective view of the hood showing the arrangement of the skirt and means (of attachment to the rim;

Figure 5 is a sectiom'zed detail of a portion of the base taken on the line 5-5 of Figure 2 showing the construction of the inlet and outlet tube connections; and

Figure 6 is a sectionized perspective of a portion of the base taken on the line 6-6 of Figure 3 showing the construction of the nozzle.

Briefly stated, the oxygen therapy unit which forms the subject matter of this invention. comprises a small completely transparent hood enclosing the head and neck of the patient, and designed to be removably attached by inlet and outlet tubes to the air conditioning machine of the standard oxygen tent, and to be snugly'sealed 2 about the neck of a patient by means of an attached skirt.

The hood is a modification of the oxygen tent principle which is designed to obviate many of th disadvantages of the large oxygen tent, namely, low oxygen concentrations, inaccessibility of the patient, difiiculty of application, and psychic phenomena such as claustrophobia and feeling of suffocation.

Referring to the illustrations, particularly Fig. l, the numeral it indicates the base of the hood, H the dome, and I2 the skirt. The base and the dome are preferably formed of Lucite, a methyl methacrylatic plastic, or any other suitable, tough, colorless, transparent material, and the skirt is made of oiled silk.

The shape of the oxygen hood is that of an eggshell bisected longitudinally. The base por- .tion iii of the hood is a wedge-shaped section of the entire oval unit upon which the dome H is mounted.

The base adjacent its upper edge is stepped inward to form a flange i3 and a ledge I l upon which the dome rests when its inner peripheral surfaoeengages the flange.

To the outer surface of the base adjacent its lower edge is located a grooved rim !5. This grooved rim is adapted to retain the skirt 52 by means of a draw string It which clamps a portion of the skirt adjacen its upper edge within the groove H in the rim.

The skirt. is formed of a pliable material such as oiled silk and is of sufiicient length to overlap posteriorly, when it is attached to the rim l5 by means of the draw string l6, as shown in Fig. 4.

The posterior edges 58 and I8 of the skirt 12 are formed with concave arcuate portions as illustrated at it and IS in Fig. 4. The edges are thus formed to adapt the skirt to contact more perfectly the curved surface of the patients neck. The skirt, which functions as a snugly fitting drape, prevents gross leakage of gas about the neck of the patient, and may be easily replaced when it becomes soiled or worn.

Two long corrugated rubber inlet and outlet tubes 29 and 253 engage nipples 2| and 2! attached to the base H3. These tubes connect the hood with the air conditioning unit 24. By means of a small flat nozzle 22 having a narrow discharge opening 23, the air current into the hood is deflected upward and carried forward along the curve of the dome. 4

The nozzle 22, which communicates with th nipple 23, may be formed integral with the base ii as shown in Figs. 5 and 6, or it may be formed as a separate unit and attached to the base.

Circulation, cooling, humidification, carbon dioxide absorption and addition of oxygen to the respired gases is accomplished by means of an air conditioning unit as used with a standard oxygen tent. When operating the hood described herein, it is necessary to change the air conditioning unit in only one respect. An additional rheostat should be added to the circuit to slow the motor down to any desired speed. The adaptability of the hood to this common type of equipment obviates the necessity of specialized equipment and is of considerable economic importance.

The air exhaled by the patient is drawn out the back of the hood via the flexible outlet tube 20 into the air conditioning unit 24 where it is cooled, humidified, carbon dioxide absorbed therefrom, and oxygen is added thereto. From the cooling chamber it is blown through the corrugated inlet tube 29 into the hood where it follows the dome of the hood anteriorly.

The technique for use of the oxygen therapy hood is extremely simple. With oxygen flowing at the desired rate and the circulating fan turned on, the hood is placed over the head of the patient in such a way that it rests on the pillow posteriorly and on the patients chest anteriorly. The patient, therefore, lies with his head on a pillow and is in contact with the hood at only one point, the chest.

As mentioned above, the skirt l2 overlaps the rim I5 posteriorly. In applying the hood the free edges l8 and iii of the skirt are crossed behind the patients neck with the arcuately curved portions l9 and I9 drawn snugly on each side thereof and the lower portion of the edges overlapped anteriorly. The end portion of the skirt is then folded once under th hood completing the application. This provides a comfortable, adequate seal which can be immediately undone, even by the patient. The application is identical for patients in the Fowler position. It is unnecessary to point out that proper application of any device for oxygen therapy contributes greatly to its emciency.

In using this hood, the general considerations of oxygen flow and air circulation are decisions to be made by the clinician in his judgment of the case. Thus, in certain cases it may be desirable V to decrease the air temperature within the hood,

Average Oxygen Concentration Liters Oxygen per min.

.Per cent 50- The hood is of great service in the treatment of various pathological conditions requiring oxygen therapy seen in a general hospital. Pneumonia, acute coronary occlusion and congestive heart failure, or where a combinationof these made up the largest group of patients. Post op- .erative patients, shock, asthma and a. number of other conditions have also been treated in this manner.

This small oxygen hood has advantages other than high oxygen concentration and its acceptability to the patient. It is safe. Mistakes in its application or in the oxygen supply will not harm the patient.

Three factors contribute largely to the patients feeling of comfort and safety; the whole tent is very light and no weight rests upon the patients head, the visibility is excellent, and the hood can be removed by the patient at a moments notice. These have overcome one of the theoretical objections to such an apparatus, the belief that many would develop claustrophobia in such a confined space. This has not been true as has been found by test.

There are certain limitations which must be realized. Any of the present types of apparatus designed for the therapeutic administration of oxygen suffer in efiiciency if they are improperly or poorly handled, and, although in clinical use the small hood gives uniformly good results with a minimum of nursing care and has obviated the need of special technicians or special duty nurses, its efiiciency will suffer with poor care.

Patients who are vomiting frequently and those who must expectorate continually are not easily handled in the hood. The latter objection does not hold true for cases in which expectoration and cough can be minimized by sedation as in lobar pneumonia.

In comparing this small hood with the large oxygen tents in use today, the greatest single advantage for the former is the fact that oxygen concentrations can be maintained that are far above the theoretical maximum concentrations obtained in the large tents. It is generally supposed that, at a flow of from 6-8 liters per minute, concentrations ranging from 40%60% are obtained in the large oxygen tents. However, it has been the applicants experience and the experience of others that such concentrations are only seen when special duty nursing care is given the patient. In fact, with ward nursing care, a maximum concentration of 40% is seldom seen unless the oxygen flow is increased to from 12 to 16 liters per minute.

In comparison with oxygen administration by nasal catheter, the hood has the advantage of being far more comfortable and acceptable to the patient, especially if therapy must be prolonged more than a few hours, and higher oxygen concentrations can be administered by means of the hood. A well placed nasal catheter is capable of providing alveolar concentrations of about 60% oxygen (comparable to inspired air oxygen concentrations of approximately 65-68%) at a flow of 6-8 liters oxygen per minute. However, the eiiectiveness is dependent largely upon the proper insertion of the catheter.

The hood has certain advantages over the face masks in popular use at this time. It is more acceptable to the patient, and more comfortable if used for periods of twenty-four hours or longer. Furthermore, in the majority of conditions which call for oxygen therapy, concentrations of 70-80% are entirely adequate for clinical purposes, barring acute surgical, anaesthetic and traumatic emergencies, where oxygen is of great value.

Having thus described our invention, what we claim as new and wish to secure by Letters Patent is: I

1. An oxygen hood comprising a base member having inlet and outlet tubes adapted to be connected to an air conditioning apparatus, a transparent oval-shaped dome mounted upon said base, and a skirt of flexible material connected to the lower portion of said base, said skirt being provided with free edges having arcuately curved portions and lower extending portions adapted respectively to be crossed behind the patients neck and overlapped anteriorly.

2. A device for administration of oxygen comprising an oval-shaped hood formed of transparent plastic material, said hood comprising a wedge-shaped base section having an upper flanged ledge portion, and a dome mounted on said flanged ledge, a grooved rim formed integral with said base portion adjacent its lower periphery, and a skirt formed of gas-tight material detachably connected to said grooved rim by means of an encircling string.

3. A device for administration of oxygen comprising an oval-shaped hood formed of transparent plastic material, said hood comprising a wedge-shaped base section provided with inlet and outlet tube connections, and an upper flanged ledge portion, a dome mounted on said flanged portion, a grooved rim surrounding said base portion adjacent its lower periphery, and a skirt formed of flexible gas-tight material detachably connected to said grooved rim by means of an encircling string.

4. A device for administration of oxygen comprising an oval-shaped hood formed of transparent plastic material, said hood comprising a base section having an upper flanged ledge formed integral therewith and upper and lower edges in anteriorly converging planes, a dome mounted on said flanged ledge, a grooved rim surrounding said base portion adjacent its lower extremity, and a flexible gas-tight skirt detachably connected to said grooved rim by means of an encircling string.

5. A device for administration of oxygen comprising an oval-shaped hood formed of transparent material, said hood including a wedge- I shaped base section provided with an inlet and an outlet tube connection, a nozzle attached to said base and communicating with said inlet tube connection, a flanged ledge formed integral with said base at its upper extremity, a grooved rim encircling said base at its lower extremity, and a skirt detachably connected to said grooved rim by means of an encircling string, said skirt having overlapping edges with oppositely located concaved portions adapted to encircle the neck of the patient, and to overlap and fold upon itself to form a seal.

6. A device for administration of oxygen comprising an oval-shaped hood formed of transparent material, said hood including a wedgeshaped base section having an upper flanged ledge and a lower grooved rim, the upper and lower periphery of said flange and said rim lying in anteriorly converging planes, an inlet and an outlet tube connection attached to the posterior portion of said base adapted to elTect communication with an air conditioning apparatus, adefleeting nozzle in communication with said inlet connection, a skirt encircling said rim with overlapping edges, each of which is formed with a contour including a centrally located concaved portion adapted to encircle the neck of the patient, said skirt being of suflicient length to be folded upon itself at its extremity to form a' gas seal.

CHRISTIAN J. LAMBERTSEN. LINCOLN GODFREY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,389,293 Blosser Nov. 120, 1945 FOREIGN PATENTS Number Country Date 826,254 French Jan. 4. 1938 

